I will honestly tell you that I built a business relationship with a branch manager who would come into my bank once a week and I would help him. Something intrigued him about me and he would ask me sales questions during his short visits. When I told him I was quiting after 2 1/2 years talking to him while working at the bank and I didn't know where I was going yet, he wanted to interview me.
Overall I would say that if you know someone or someone who knows a staffing firm connection do that first. These companies that are legit do not post openings. I interviewed with a couple companies that posted openings and it seems like they always had high turnover due to horrible management or company politics. If the vibe is weird then don't pretend it will be great.
Background wise, I have my bachelors in business. It plays a good part but it may not be necessary if you know someone.
Essentially, if you can get your foot in the door and impress the hiring manager you should be golden. If you need any other tips let me know. I work for a great staffing company.